WASHINGTON  Two airborne planes -- one landing and the other taking off -- came within a half-mile of colliding at John F. Kennedy International Airport on Friday in the second such incident at the airport in a week, the Federal Aviation Administration said.

The FAA moved quickly to change takeoff and landing procedures at JFK on perpendicular runways -- the kind of runways involved in both incidents.

FAA spokeswoman Laura Brown said a Delta Flight 123 was arriving at the airport Friday when the pilot decided to abort his landing and execute a "go-around" -- a routine procedure often used during heavy congestion. That caused the Delta flight to intersect with the flight path of Comair Flight 1520, a regional jet that was taking off on another runway.

The FAA ordered new procedures Friday afternoon to change the way takeoffs and landings on perpendicular runways are sequenced, Brown said in an interview with The Associated Press.

The new procedures are designed to ensure "that aircraft of one runway clear out of the path of the other runway before the second flight comes down on the other runway," Brown said. "We've had two events recently and I think we want to make sure the appropriate safety margins are in place."

Last Saturday, a Cayman Airways flight was landing at JFK when the pilot decided to abort the landing a fly around the airport again as a LAN Chile jet was taking off. Their flight paths crossed, bringing the planes within about 200 feet of each other vertically and a half-mile horizontally. The National Transportation Safety Board is investigating that incident.

On Friday, the Delta jet, a Boeing 757, and the Comair plane, a Bombardier CRJ9, came within 600 feet of each other vertically and a half-mile horizontally, the FAA said.

The agency said it was not classifying either incident as a "near collision" because there was no violation of standards for how apart planes can fly, Brown said.

Delta spokeswoman Gina Laughlin initially said the incident took place a week ago on July 4. However, Laughlin later told The Associated Press that the FAA was correct, and the incident took place on Friday at 1:20 p.m. Comair is a subsidiary of Delta.

"This did happen today," Laughlin said. "This is what we call, and what the FAA classifies, as a 'proximity event.'"

Laughlin said she didn't know how many people were aboard the Delta flight, which came from Shannon, Ireland, but the plane seats 170 passengers.

Dean Iacopelli, a representative for the New York National Air Traffic Controllers Association, said the FAA has "terminated that perpendicular simultaneous approach procedure."

Barrett Byrnes, who president of the controllers union at the JFK tower, said controllers have long sought the procedure changes.

"The FAA put out an order to JFK to no longer use that approach. That's exactly what we wanted to happen," Byrnes said. "We've been trying to change that for the last 12, 13 years. It's been an accident waiting to happen."

Friday's incident began when the Delta flight was handed off from the FAA's traffic control center in Westbury, N.Y., to the JFK tower as the plane prepared to land. In the handoff, the Delta pilot apparently wasn't using the communication frequency the flight was assigned to communicate with the JFK tower, Brown said.

The JFK tower and the Delta jet did not establish contact until the flight was 1.5 miles from touching down on the runway, Brown said. The flight was cleared to land by the tower, but the pilot decided to abort the landing, Brown said.

___

Associated Press writer Marcus Franklin in New York contributed to this report.

Copyright 2008 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

A passenger aircraft waits on a taxiway as another takes off from a farther runway at Newark Liberty International Airport in this June 27, 2008 file photo in Newark, N.J. Two airborne planes -- one landing and the other taking off -- came within a half-mile of colliding at New York's John F. Kennedy International Airport on Friday in the second such incident at the airport in a week, the Federal Aviation Administration said. (AP Photo/Mel Evans, file)